Diff Fluid Flow Indicating Meter

An instrument designed to measure the rate of flow of a fluid through a pipeline, based on the exact relation which differential pressure bears to fluid velocity, and this measurement indicated on a graduated scale by a pointer directly connected to a mercury or oil sealed bell or a bellows. It may or may not have a totalizing integrator register built in. Excludes: meter, flow rate indicating; meter, fluid flow indicating, electromagnetic; and meter, fluid flow indicating, ultrasonic.